Vacuum draft control system for variable spinning



Aug. 28, 1956 A. A. sPlsAK ErAL 2,760,237

VACUUM DRAFT CONTROL SYSTEM FOR VARIABLE SPINNING RMA/5); Mir/:5, Eager A/ MfA/ENNY Kimm. www? H TToENEys Aug. 28, 1956 A, A, SPISAK ET AL 2,760,237

VACUUM DRAFT CONTROL SYSTEM FOR VARIABLE SPINNING Filed March 9, 1955 s shee'ts-sheei 2 INVENTORS HNPREW H. Slo/514K BYPD/MO/V O. PEEPHULT HTToeA/E YS 5 Sheets-Sheet 3 A. A. SPISAK ETAL VACUUM DRAFT CONTROL SYSTEM FOR VARIABLE SPINNING Aug. 28, 1956 Filed March 9, 1953 INVENTORS HNDPE W H. SID/SHK EffMON 0. PERRHULT EDGE/Qi ON HVSA/EMM)I HToe/vfjs United States Patent O VACUUM DRAFT CONTRL SYSTEM FR VARIABLE SPG Andrew A. Spisak and Raymond 0. Perrault, Cleveland, Ohio, assignors to The Warner & Swasey Qompany, Cleveland, Ohio, a corporation of Ohio Application March 9, 1953, Serial No. 34l,252

4 Claims. (Cl. 19-131) The present invention relates to fiber drafting and concerns particularly the drafting of strands of fibers preparatory to spinning and other operations for preparation of textile yarns and threads. The invention may be practiced with any type of fiber strands, such as tops, slivers, rovings, slubbings, and the like in bundles or aggregates, all of which for convenience are referred to as fiber strands or slivers.

An object of the invention is to achieve improved control of the bers in the strand during drafting and to achieve effective control of various kinds of fibers natural or synthetic, or blends thereof in the case of natural fibers whether of animal or vegetable source, and in the case of synthetic bers whether smooth or crimped. Moreover, it is an object to accomplish such liber control for various liber lengths as well as for strands composed of a mixture of fibers of different lengths.

A further object of the invention is to provide an improved draft control unit, readily adjustable for different fiber lengths, and easily opened and closed for insertion of fiber strands.

Still another object of the invention is to obtain a high degree of reduction in each drafting stage and to produce very tine yarns with relatively few drafting stages.

lt is also an object to avoid difficulty with breaking of fibers in the strand and to produce drawn slivers of a high degree of uniformity of weight and thickness.

Other and further objects, features and advantages will become apparent as the description proceeds.

ln carrying out the invention in accordance with a preferred form thereof, a plurality' of drafting units are mounted upon sloping sides of a suction header for supplying a large number of spinning heads simultaneously. Two drafting zones are provided for each sliver and improved draft control is provided in each. In the iirst drafting zone a plurality of slivers are drafted simultaneously to be combined and further drafted as a single strand in the second zone. In the first zone a multipleslot trumpet guide is provided for supplying the slivers to the ratch. Ratch rolls and draft rolls are provided. For accomplishing effective draft control, upper and lower belts or aprons are provided for contacting and enveloping the strands. Each apron passes around one of the ratch rolls and is guided directly into the nip of the draft rolls. Moreover, an apron nip pressure roll is provided for increasing control over the fibers of the strands. An adjustable mounting is provided for the pressure roll to accommodate in the same apparatus different strands which may differ in average maximum lengths of ber.

For retaining full fiber control into the very nip of the draft. rolls, the lower apron is so constructed as to be air pervious and a suction box is provided lfor applying vacuum to the under surface of the portion of the lower apron at the exit end of the drafting ratch.

In order to permit the draft control apparatus to be opened and closed readily when slivers are to be inserted,

2,760,237 lfatented Aug. 28, 1956 or a change in set-up is to be made 0r the like, a pivotallymounted frame-wor`k is provided which supports the upper ratch roll, apron nip pressure roll, apron nip guide, and upper apron. This frame-work, and likewise the upper draft rolls, are provided with quick-release latches.

A better understanding of the invention will be provided by the following detailed description considered conjunction with the accompanying drawings in which:

Fig. l is an end elevation of vacuum draft control apparatus for variable spinning;

Fig. 2 is a view of the irst zone draft control unit corresponding to Fig. l but showing the unit tilted to a horizontal base;

Fig. 3 is a view corresponding to Fig. 2 but partially in section represented as cut by a vertical broken plane, showing also in broken lines the upper apron and mounting swung up into open position, and showing in broken lines an alternative extreme portion of the pressure-roll mounting; the cutting planes for sectional representation are indicated at 3A and 3B in Fig. 4, the plane 3B being taken through the hollow pedestal;

Fig. 4 is a plan view of the suction box with the plate along which lower apron moves, partially broken away to expose air channels to slots for separate slivers and fragmentarily showing lower, air-pervious aprons;

Fig. 5 is a cross-section cut by a plane 5 5 indicated TFig. 4, and

Fig. 6 is a fragmentary end View showing a pivoting mounting for the unit of Fig. 2.

Like reference characters are utilized throughout the drawings to designate like parts.

ln the embodiment of the invention illustrated there is a suction header il which may extend the length of the spinning room, having sloping sides 12 for carrying a plurality of drafting units 13 and 14 mounted side by side. Since in the view of Fig. l the drafting line is seen from one end, only one first-zone drafting unit 13, and one second zone drafting unit 14 are visible. Drafting units are shown on only one side to simplify the drawing, but it will be understood they may be mounted on both sides if desired. As shown, the first-zone drafting unit 13 is arranged to receive a plurality of slivers l' and to reduce these to much lighter strands 16. The second-zone unit 14 is arranged to receive the strands 16, combine them into a single strand and reduce the combined strand further to a tine yarn 17, suitable for supplying to one of a conventional long bank of spinning heads (not shown).

The suction header 11 is fabricated of sheet metal or the like to form a suction duct 1S, roughly of inverted V-shape in cross-section. Horizontal sheets 19, joined to the outer walls l2 and inner walls 21 serve to form an enclosed space constituting the suction duct i8, and to isolate this space from chambers 22. A suitable suction fan or pump (not shown) is connected to the suction duct 18a at the far end with respect to the view presented by Fig. l, in order that all of the drafting units of the bank may be supplied with suction. Suitable means are provided for avoiding a pressure drop along the length of the duct as described in the copending application of Andrew A, Spisak Serial No. 337,545, tiled February 1S, 1953. Openings 23 and 24 are provided in the side walls 12 of the suction header to cooperate with hollow pedestals 25 and 26 for supporting the drafting units 13 and i4, respectively, and through which suction connections to drafting control elements are made.

The rst-zone drafting unit 13 is illustrated to a larger scale and more in detail in Figs. 2 and 3. To effect drafting of the strand, the unit 13 includes upper and lower feed rolls 27 and 28, respectively, and upper and lower draft rolls 29 and Si), respectively. To control the fibers during drafting, a combination of three features is employed, apron control, vacuum control and roll pressure control. To this end upper and lower aprons or belts 32V and 33 areV provided. A suction box 34 is provided having air-inlet slots 35, shown in Fig. 4, under the portion of the lower apron 33 near the draft roll nip; and the lower apron 33 is made air-pervious, preferably with rows of perforations36 aligned with the slots 35. In addition an apron nip pressure roll 37 is provided, which is 'arranged for adjustment of its position along the sliver 15. As indicated by the fragmentary view of Fig. 4, a twin unit construction may be employed with duplicate sets of rolls, aprons and the like mounted on either side of a common pedestal 25.

To facilitate threading sliver between the aprons and thedraft rolls when starting the apparatus or for other reasons, the draft control units are made openable. This is accomplished by mounting the upper apron and rolls upon a pivoted framework 38, comprising a longitudinal bar 39, a vertical post 41, `and a pivot bolt 42, secured in a clevis 43 carried by a bracket 44, forming a part of the mounting assembly for the lower apron and the suction box. The lifted or open position is indicated by dashed lines in Fig. 3, the full lines showing the parts in closed or operating position.

F or further'improvement in operating eiciency in connection with making adjustments and replacing the lower apronv when necessary, the lower apron and suction box mounting assembly is also made movable, being removably secured to the hollow pedestal 25.

The lower draft roll 30 is secured to a drive shaft 45 which is common to all the drafting units of the bank for directly driving the lower draft roll. The upper drive roll 29, of greater diameter is indirectly driven by the friction transmitted from the lower roll 30 through the sliver 16.

The lower apron 33 is provided with a driving roll 46 secured to a drive shaft 47 which is common to all the apron drive rolls of the bank. Idler rolls 48, 49 and 50 are provided to keep the belt 33 taut and give the drive 'roll 46 enough contact with the belt 33. The lower feed Vroll28 is driven through the belt 33 by the apron drive roll: 46. All other rolls are individually driven'as a result of force transmitted frictionally from one of the V'drive rolls through the aprons or the slivers or both.

The lower assembly of the draft control unit comprises l"therhollow pedestal and the suction box 34. The suction box 34 hasa depending lthroat portion 52, adapted to t against the upper end of the pedestal 25 and form a connection with the interior thereof, the suction box 34 being removably secured to the pedestal 25. The suction box 34 comprises a casting 53 with a plurality of ducts 54 formed therein leading to the slots 35 and communi- 'eating with the throat portion 52. Side plates 55 are 'secured to the casting 53 on either side thereof as shown in Fig. 2. The casting 34 is recessed to receive a sheet metal member 56 forming a well 57 adapted to receive i the plates 61 are formed linto lips serving as front guides for lower aprons 33.

Ears 63, 64 and 65 are formed in the side plates 55 for pivotally supporting arms 66, 67 and 68, carrying the idler rolls 43, 49 and 50 respectively. An adjusting screw 69 is provided for causing the arms 66 to hold the roll 48 and the lower apron 33 in close proximity to the apron drive roll 46. A telescoping strut member 7-1 is also provided, containing a compression spring 72 for resiliently extending Ythe member. The strut 71 is pivoted at the ends by means of pivot pins 73 and 74 toi-the arms 67' and 68 for resiliently holding these arms apart to maintain the lower belt 33 taut and press the roll 49 and the apron 33 around and against the drive roll 46. As shown, the pivot pin 73 is located at a greater'distance from the supporting pivot of `the arm 67 than the pivot pin 74 from the support of the arm 68. Consequently, the spring strut 71 exents the greater leverage upon the ann 67.

Means are provided for relieving the suction and the drive to the lower apron by pivoting the suction box assembly 34 in the event of fibers wrapping around'the draft roll 30. To this end a projecting notch 76 is formed on the pedestal 25, and a pivot pin 77 isxed on `an arm 81 (shown in Fig. 6) depending from the casting 53, for-ming a part of the suction box assembly 34, for pivotally supporting the draft unit in the notch 76.

For yieldably securing the suction box assembly 34 to the hollow pedestal 25, a machine screw 78 is provided having a head 79 and a threaded tip 80 as shown in Fig. 2. A counterbored opening 82 in the cover wall of the casting 53 is provided to receive the head 79 and a tapped hole 83 is provided in a nose portion 84 of the hollow pedestal 25. An abutment 85 is provided at the front of the throat portion 52 of the suc tion box 34, for providing a bearing surface for a compression spring 86 surrounding the screw 78 and fitting yunder its head 79 whereby the spring 86 normally urges the suction box assembly 34 and throat portion 52 downwardly to close the joint 51 with the hollow pedestal 25`for maintaining suction.

If there should be an unusual uneveness of the bers or for other reasons a great mass or bunch of fibers reaches the draft rolls 29 and 30 pressure is produced which is great enough to lift the suction box assembly 34 against the force of the springs 86 and 113. The suction box assembly 34 and the holddown subassembly for the upper draft roll 29 including the member 112 are interconnected so that bodily movement of the holddown subassembly away from the suction header wall 12 is imparted to the suction box assembly 34. Thereupon the assembly pivots around the pin 77 from the position shown in full lines in Fig. 3 to that shown in Fig. 2, separating the structure from the hollow pedestal 25 so'as to form an opening 51 relieving the suction. As the assembly rises, pivoting around the pin 77, members 66 and 67 carrying the idler rollers 48 and 49 also rise loosening the apron 33, discontinuing the effect of the drive vroll 46 thereon and thus relieving the lower apron drive. The assembly including the machine screw 78 and spring 86, thus provides for a small angle of movement of the drafting unit around the pivot pin 77.

The pivoted framework 38 for the upper apron and rolls carries bearing brackets 87 in which the upper ratch roll 27 is mounted, and bearing brackets 88 in which the pressure roll 37 is mounted. The bearing brackets 88 are secured to a carriage 89 which is adjustably secured to the longitudinal bars 39. As indicated in Fig. 3 the carriage 89 is slidable along the bars 39 and may be secured in any position thereon from that shown in full lines to that shown in dashed lines in Fig. 3.

A spring mounting is utilized, including compression springs 91 for yieldably pressing the roll 37 against the portion of the upper apron 32 contacting the sliver 15. For adjusting spring pressure, adjusting screws 92 may be provided.

For the purpose of guiding the upper apron 32 into the nip of the draft rolls 29 and 30 a pivoted sheet metal guide member 93 is provided having a curved lip 94 around which the apron 32 slides. The guide 93 is secured to pivot pins 95 journaled in the side frame bars 39 and is urged into contact with the upper apron 32 by means of a rat-trap spring 95a, for forming an auxiliary nip.

Multiple trumpet guides 97 are provided having suitable slots forreceiving the sliversV 15 and feeding them between the portions of the aprons 32 and 33 aligned with the apertures 36 in the lower apron 33 and slots 35 in the plate 61. A spring-pressed ball detent 98 may be provided for releasably holding the upper apron framewo'rk 38 in the raised position.

For securely fastening the framework 38 downward in the operating position shown in full lines in Figs. l, 2 and 3, a latch mechanism is provided. The latch mechanism comprises a center post 101 secured to the twin-unit suction box 34 between apron units, and a latch lever 102 pivoted to the post 96 by a screw 103. The latch lever 102 is provided with an offset or nose 104 fitting a slot 105 in the post 101. The post 96 is iixed to the bar 39 carried by the upper framework 38.

In order that the draft rolls 29 may be held down with adequate pressure, but the pressure may be relieved quickly in case of necessity for shutting down a section of the spinning frame, a quick release hold-down mechanism is provided. This takes the form of pivoted roll hold downs 106 adapted to bear against stub shafts 107 of the upper draft rolls 29, the stub shafts being adapted to ride between the edges of members 106 and 112. For yieldably pressing the members 106 downward, a lever 103 is provided, having nose portions 109 adapted to bear down on the hold downs 106, pivoted by pins 111 at the upper end of a vertical member 112 held down yieldably by a tension spring 113. The member 112 is formed with a head 114 receiving the pivot pins 111 and also receiving pivot pins 115 for the hold downs 106. The central portion of the member 112 is in the form of a rectangular post fitting a rectangular notch 116 as shown in Fig. 4 formed in the suction box casting 53. That portion of the member 112 beneath said central portion thereof is wider than the slot 116 so that when the member 112 is moved outwardly away from the wall 12 of the suction header and against the action of the spring 113 it carries the assembly 34 from the position shown in Fig. 3 to the position shown in Fig. 2.

At the lower end of the member 112 a slot 117 is provided cooperating with a guide pin 118 in a block 119 secured to the base of the pedestal 25.

As the previously mentioned bunching of the bers or cascading of the fibers takes place and the fiber builds up between draft rolls 29 and 30, in case of abnormal operation, a force is produced which is great enough to overcome the force of the spring 113 and lift the upper draft roll 29 with its assembly attached to the arm 112 in an upward direction, thereby taking the draft roll 29 out of contact with the draft roll 30 as shown in Fig. 2, in addition to breaking the vacuum at the opening 51.

For normal operation, the framework 38 for the upper apron 32 is held down with the latch 102 engaging the slot 105 and the draft roll hold down lever 108 is in the vertical position shown in Fig. 3 in full lines. Rotative power applied through the drive shaft 45 causes the draft rolls 29 and 30 to draw the sliver 15 out while the fibers therein are controlled and confined by the suction applied from the slots 35 through the apertures 36 in the lower belt 33, and the bers are compacted by the pressure of the roll 37.

The interfrictional grip between fibers produced by the suction cooperating with the upper and lower aprons causes only those bers to be pulled out during drafting which are actually nipped by the draft rolls 29 and 30. The forward movement of the remaining fibers is controlled by the surface speed of the apron 33. The second stage unit 14 shown in Fig. l operates in a similar manner to attenuate the slivers 16 further after combining them into a single strand to form the sliver 17.

lf it is desired to draft slivers having longer fibers the pressure roll mountings 89 and 58 are moved from the position shown in full lines in Fig. 3, toward the position shown in dashed lines in Fig. 3 after releasing the latch lever 102 to permit the framework 38 to take the position shown in dashed lines in Fig. 3. For releasing the upper draft roll 29 to permit inserting the end of a new batch of iibers the hold down lever 108 is moved to the position shown in Fig. 3.

Lifting the suction box 34 from the hollow pedestal 25 releases the tension on the lower apron 33 permitting examination or replacement thereof. When the suction box 34 is replaced the adjusting screws 69 and spring 72 and rolls 48 and 49 wrap the apron around the apron drive roll 46, enabling the roll 46 to control the linear surface speed of the apron 33 so as to maintain it at a lixed value less than that of the draft roll 30.

While the invention has been described as embodied in concrete form and as operating in a specific manner in accordance with the provisions of the patent statutes, it should be understood that the invention is not limited thereto, since various modifications will suggest themselves to those skilled in the art without departing from the scope of the invention.

What is claimed is:

l. A draft control apparatus for textile fibers comprising in combination with a suction header having an opening therein, a hollow pedestal mounted to close said opening in said header and a draft control unit pivotally secured to said hollow pedestal, adapted to pivot between iirst and second positions toward and away from the pedestal, and having a suction opening therein adapted to fit a corresponding opening in the hollow pedestal and close the opening with the draft control unit in its dirst position against the pedestal and to relieve the suction with the draft control unit in its second position, a suction box having a suction passageway connected to the opening in said pivoted draft control unit, said suction box having a surface plate with longitudinally extending openings leading from said suction passageway, an air pervious apron with means for causing it to move longitudinally along said suction box openings over said surface plate and means cooperating with said apron for holding slivers against said apron.

2. Apparatus as in claim l wherein the last mentioned means comprise a second apron with means for supporting it along the rst apron for sliver feed therebetween.

3. A draft control unit for association with a pair of drafting rolls for strands of textile fibers, said unit comprising in combination a suction box, pressu-re roll means, strand-contacting apron means with supporting means for passing said apron means longitudinally of itself under said pressure roll means, and along said suction box and toward said drafting rolls, said apron means having an air pervious zone toward said suction box, the portion of said suction box between said pressure roll means and the drafting rolls having longitudinally extending openings registering with said apron air pervious zone, whereby the fibers of the strand being drafted are compacted and maintained in interfrictional engagement as they approach the drafting rolls, said pressure roll means comprising a strand-compressing pressure roll mounted above the strand-contacting apron means more distant from the drafting rolls than said suction box openings, said suction box being recessed to receive a reaction pressure roll mounted below said strand-contacting apron means positioned to receive the force of said strand-compressing roll.

4. A draft control unit for association with a pair of drafting rolls for strands of textile fibers, said unit comprising in combination a suction box, pressure roll means, strand-contacting apron means with supporting means for passing said apron means longitudinally of itself under said pressure roll means, and along said suction box and toward said drafting rolls, said apron means'having an air pervious zone toward said suction box, the portion of said suction box between said pressure roll means and the drafting rolls having longitudinally extending openings registering with said apron air pervious zone, whereby the fibers of the strand being drafted are compacted and maintained in interfrictional engagement as they approach the drafting rolls, said pressure roll means comprising a strand-compressing pressure roll mounted above:

the strand-contacting apron means more distant from the, drafting rolls than said suction box openings, said suction box` being recessed to receive a reaction pressure roll mounted below said strand-contacting apron means positioned to receive the force of said strand-compressing roll, and longitudinally adjustable supporting means for said pressure rolls to adapt the apparatus to different maximum lengths of fibers in strands to be drafted.

References Cited in the file of this patent UNITED STATES PATENTS Rushton Oct. V27, 1925 Honda Nov. 23, 1937 Honda Dec. 5, 1939 Lundgren July 1, 1947 Sandelin Nov. 24, 1953 

